Fish parasites as indicators of organic pollution in southern Brazil

Abstract

Increasing urbanization along riverbanks is a constant source of stressors to the aquatic community, and the use of bioindicators is suitable to detect and monitor the effect of each stressor. We investigated the parasites of the 'cará' fish (Geophagus brasiliensis) as potential bioindicators in a river whose banks are subject to increasing anthropogenic pressure. Samples were taken at four points of the Sangradouro River, in Florianópolis, southern Brazil, bimonthly for 12 months. Water temperature, pH, dissolved oxygen, conductivity and salinity were measured at each point and water samples were taken for nutrient analysis (total nitrogen, nitrite, total ammonia nitrogen, total phosphorus, phosphate), and total and faecal coliforms. A generalized linear model (GLM) was constructed using the abundance of each parasite species as the response variable and biometric characteristic of the fish and water variables as possible predictors. Among the 137 fish examined, 114 (83.2%) were parasitized by at least one parasite species. Two species of ectoparasites (Sciadicleithrum guanduensis and Neascus-type metacercariae) and two species of endoparasites (Pandosentis aff. iracundus and Homalometron pseudopallidum) were observed. This is the first record of the genus Pandosentis in Brazilian waters and the first record of the species G. brasiliensis as a host for this parasite. Among the analysed groups of parasites, monogeneans and acanthocephalans proved to be the most sensitive to the concentrations of dissolved oxygen, faecal coliforms and total ammonia nitrogen in the water. Our study suggests that the abundance of both monoxenic and heteroxenous parasites can be negatively affected by organic pollution in the aquatic environment, reinforcing the potential of fish parasites as indicators of water quality.

Metacommunity of a host metapopulation: explaining patterns and structures of a fish parasite metacommunity in a Neotropical floodplain basin

“…In addition, abiotic features had a significant influence on ectoparasite diversity in the dry period. This result can be explained by the fact that ectoparasites are more exposed to the local environmental conditions, mostly for their probability of infection, because most ectoparasites have monoxenic life cycles (Poulin, 2011;Krasnov et al, 2015;Lacerda et al, 2017). Other studies analyzing the contribution of environment and host traits also found a relationship between parasites and environmental features, mainly for monogeneans (Berkhout et al, 2019).…”

Kimia Fisik Perairan dan Ektoparasit Ikan Nila dan Patin Di Situ Gintung, Tangerang Selatan, Banten

“…Danau atau situ menyediakan berbagai macam fungsi dan layanan seperti sumber air minum, rekreasi, berenang, memancing, budidaya ikan dan populasi habitat flora dan fauna yang memiliki nilai ekonomi yang tinggi (Reynaud dan Lanzanova, 2017). Selain memiliki keuntungan berdasarkan nilai ekonomi, fungsi dan layanan tersebut memiliki kerugian terhadap ekosistem danau seperti menurunnya kualitas perairan (Kagalou et al, 2003), meningkatnya polusi di air (Chen et al, 2016;Su et al, 2016), berpotensi mengganggu terhadap kesehatan manusia (Zhang et al, 2009), dominansi biota, keanekaragaman yang menurun (Cai et al, 2012) jika dibandingkan dengan danau yang tidak ada gangguan antropogenik (Lange et al, 2013) dan mempengaruhi keberadaan parasit di ikan (Lacerda et al, 2018).…”

“…Menurut Amirullah dkk., (2012), insang dapat menyediakan sumber makanan berupa darah dan media yang cocok bagi Dactylogyrus untuk dapat bereproduksi secara maksimal, berkembangbiak dengan cepat dan tidak memiliki inang spesifik sehingga dapat menginfeksi semua jenis ikan. Lebih lanjut, Dactylogyrus ditemukan pH perairan yang asam sampai dengan netral (El Amin dan Al-Harbi, 2016) dan sensitif terhadap konsentrasi DO, feacal coliform dan total nitrogen (Lacerda et al, 2018). Selain Chilodonella dan Dactylogyrus genus ektoparasit yang ditemukan pada ikan patin di Keramba Jaring Apung (KJA) Situ Gintung adalah Litonotus yang memiliki nilai prevalensi sebesar 20%.…”

Parasitological diagnosis in food fish produced in a fish farm, in the Zona da Mata, Minas Gerais, southeastern Brazil

“…Hence, fish become more susceptible to parasitic infections (as a result of an immunological imbalance) that may cause considerable mortalities, especially if there is a secondary bacterial or viral infection (Noga, 2010;Jerônimo et al, 2012). Ectoparasite communities such as protozoans, monogeneans, digenean larvae and crustaceans (Jerônimo et al, 2015) present in cultured fish in the facilities could be used as bioindicator of environmental and fish health status (Antonelli et al, 2016;Lacerda et al, 2018) in order to improve and implement the best management practices.…”